Direct links to fixes
APAR status
Closed as program error.
Error description
In certain circumstances, especially when a large number of files have been deleted, for example through expiration, the bfDerefQueueThread thread can hold an excessive number of locks. This can then cause database lock escalations. When lock escalations are occurring, there will be a noticeable slow down of the server performance. It is also likely that the active log space will begin filling as database transaction processing takes longer. This could cause a server outage if the log space fills. To see if you are affected by this problem, verify that there are 'LLM-memory low' messages and lock escalations messages in the db2diag.log file. For example: Locking memory management: LLM-memory low. Escalation threshold activated. LLM-lock list size = 148650000 LLM-lock list available = 1936 ADM5501I DB2 is performing lock escalation. The affected application is named "dsmserv", and is associated with the workload name "SYSDEFAULTUSERWORKLOAD" and application ID "*LOCAL.tsminst1.140929162329" at member "0". The total number of locks currently held is "3733", and the target number of locks to hold is "1866".
Local fix
Increase the DB2 LOCKLIST for the database. To find an appropriate value by which to increase the LOCKLIST, first run the commands below to find the count of dereferenced chunks per node/fsid in the BF_DEREFERENCED_CHUNKS table: $ db2 connect to tsmdb1 $ db2 "select nodeid, fsid, count(*) from tsmdb1.BF_DEREFERENCED_CHUNKS group by nodeid, fsid" > bfdc_count.txt In the 'bfdc_count.txt' output file, find the largest value in the third column, which represents the number of dereferenced chunks for a node/fsid combination. Say for example that '40,000,000' is the largest number in that column. Also assume that each lock consumes 128 bytes of memory and that the LOCKLIST value represents the number of 4096-byte pages. Increase the LOCKLIST by a number sufficient to handle '40,000,000' by calculating as below. In this case you want to increase the LOCKLIST by 1,250,000- 40000000 * 128 bytes / 4096 bytes = 1250000 So if your current LOCKLIST is set to '500000', increase that number by 1250000 by setting a new LOCKLIST of 1750000. For steps to change the lock list in the database configuration, refer to the documentation at the link below- http://www-01.ibm.com/support/docview.wss?uid=swg21430874
Problem summary
**************************************************************** * USERS AFFECTED: * * All Tivoli Storage Manager server users. * **************************************************************** * PROBLEM DESCRIPTION: * * See error description. * **************************************************************** * RECOMMENDATION: * * Apply fixing level when available. This problem is currently * * projected to be fixed in level 7.1.5. Note that this is * * subject to change at the discretion of IBM. * ****************************************************************
Problem conclusion
This problem was fixed. Affected platforms: AIX, HP-UX, Solaris, Linux, and Windows.
Temporary fix
Comments
APAR Information
APAR number
IT04946
Reported component name
TSM SERVER
Reported component ID
5698ISMSV
Reported release
71A
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt / Xsystem
Submitted date
2014-10-15
Closed date
2016-02-04
Last modified date
2016-02-04
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
Fix information
Fixed component name
TSM SERVER
Fixed component ID
5698ISMSV
Applicable component levels
[{"Business Unit":{"code":"BU029","label":"Software"},"Product":{"code":"SSGSG7","label":"Tivoli Storage Manager"},"Platform":[{"code":"PF025","label":"Platform Independent"}],"Version":"7.1.3"}]
Document Information
Modified date:
28 August 2023